Application of Electronic Nose and Infrared Thermography to detect physiological disorders on apples (Golden Delicious and Stark Delicious

The agri-food products contain a variety of information, directly related to their quality, traditionally measured by means of tedious time consuming and destructive analysis. For this reason, there is a growing interest in easy to use, rapid and non-destructive techniques useful for quality assessment. The objective of this study was to evaluate the possibility of using Electronic Nose (EN) and Thermography (Th) for differentiate typical external apple diseases: in particular, physiological, pathological and entomological disorders have been examined. The work was set to ensure that these technologies were able to identify the presence of the diseases regardless of the position of the fruit during the sorting process. The data obtained were processed with chemometric analysis. Linear Discriminant Analysis (LDA) was applied to EN data in order to classify healthy apples and those affected by physiopathology. The sample analyzed by Th, were submitted to physical measurements (weight, diameter, volume and density) and the collected data were analysed by Principal Component Analysis (PCA). Thermo-camera was able to distinguish healthy apples from those with physiological disorders, but the identification of the physiological disorders was less evident. These preliminary results showed that the EN is particularly useful to identify and discriminate apples affected by disorders suggesting that this device could be used for the monitoring of fruit on the sorting line or in the storage rooms.